This pattern is behaving very predictably, based on yellow fever behaviors documented since 1797, and some of the vibrio cholera patterns in U.S. soil since 1832. There is a northward transgression of mosquito born diseases (for obvious reasons). As documented in some west nile work from 2000-2005, ecological methods may be used to predict ecosystems most likely to harbor the species that serve as the most active vectors. (see my canopy light penetration field work for starters – at https://brianaltonenmph.com/west-nile/west-nile-surveillance-2/&nbsp;).

Further comparing vibrio and chikungunya, vibrio is water dependent and ecologically bound to it deltaic settings (i.e. New Orleans and Galveston area–though some will dispute me about this), and is fully dependent upon isopods. On the other hand, chikungunya behaves according to mosquito patterns much like the yellow fever and dengue, and lacks the stricter peri- and subaquatic requirements.